I’ve just gone through the wiley study guide and I am wondering why we do not use interest rate compounding when discounting for forward rate agreements. I.e when discounting the PV or annualising, we use simple interest (e.g. (30/360) x1 + i).

Comparing this with discounting forwards on equity and currencies, where compounding is used with the time factor as the exponent (1+i)^30/360.